Dark matter, a mysterious substance that exhibits gravitational attraction but does not emit light, may actually be made up of huge clusters of ancient black holes created at the very beginning of the universe, according to a new study.
This conclusion was made based on the analysis of gravitational waves or ripples in space-timecaused by two distant collisions of black holes and neutron stars…
Ripples – with inscription GW190425 and GW190814 – were discovered in 2019 by the Laser Interferometer Gravitational Wave Observatory (LIGO) in Washington and Louisiana and the Virgo Interferometer near Pisa, Italy. Previous analysis showed that the ripples were caused by collisions between black holes, which are 1.7 to 2.6 times the mass of our Sun, and either a smaller neutron star or a much larger black hole.
But it would do one of the objects on each collision, what astrophysicists call a black hole with the mass of the Sun, roughly the mass of the Sun.
Connected: 10 finds of huge black holes
“Solar mass black holes are quite mysterious because they are not expected from traditional astrophysics,” like star explosions or supernovae that turn larger stars into black holes, study lead author Vladimir Takhistov of the University of California, Los Angeles. Angeles, told Live Science in an email.
Instead, the authors suggest in a study published Feb.16 in the journal Physical Check Lettersthese solar-mass black holes may be the “primordial” black holes created during the Big Bang. Or they could have formed later, when neutron stars were converted to black holes – either after absorbing primordial black holes or after absorbing certain supposed types of dark matter, the mysterious matter that exerts a gravitational pull does not interact with light, Tachistov said.
Primal black holes
The original black holes, if they exist, were probably created in huge numbers in the first second of the Big Bang, about 13.77 billion years ago. They would be of all sizes – the smallest would be microscopic and the biggest tens of thousands of times the mass of our Sun..
Calculations show that the smallest have so far “evaporated” by emitting quantum particles in a process known as Hawking radiation, so that only primordial black holes weighing more than 10-11 kilograms – roughly the mass of a small asteroid – still exist today.
If they really existed, these ancient black holes could form huge halos of “dark matter” flanking galaxies, some astrophysicists believe.
The researchers wanted to see if they could distinguish primordial black holes from black holes that formed from neutron starstwinkling supernova remnants left after their parent stars exploded after using up all their hydrogen in nuclear power. merger reactions.
Astrophysicists have calculated that stars, which are about five times the mass of the Sun, collapse, leaving behind a neutron star of superdense matter, while the mass of our Sun is approximately equal to the mass of the city. Living science reported…
According to this theory, the strong gravity of some neutron stars would constantly attract dark matter particles; The new study suggests that eventually their gravity will become so great that the neutron star and dark matter will collapse together into a black hole.
An alternative proposed by the study is that the neutron star could be attracted and merged with a small primordial black hole, which then settled at the neutron star’s center of gravity and fed on surrounding matter until only the black hole remained.
Takhistov and his colleagues reasoned that black holes transmuted from neutron stars would have to follow the same mass distribution of neutron stars from which they originated, which depends on the size of their parent stars.
With that in mind, they looked at data from 50 or so gravitational wave detections made to date and found that only two – GW190425 and GW190814 – are associated with objects with the correct mass to be primordial black holes, the study authors write.
The study is not conclusive: it is still possible that neutron stars of detected masses or black holes transmuted from neutron stars of this size were involved in these two collisions. But the authors write that the mass distribution of neutron stars supposedly existing in the universe makes this unlikely.
“Our work is a powerful test for understanding their origin and connection with dark matter,” Takhistov said. “In particular, this test demonstrates that black holes significantly heavier than about 1.5 times the mass of the Sun are very unlikely to be ‘transmuted’ by black holes as a result of the destruction of neutron stars.”
And if so, it hints that primordial black holes may indeed exist and that they may be a component of dark matter, according to the study.
This method will become more accurate as more gravitational waves are detected, Takhistov said: “The test is statistical in nature, so collecting more data will allow for better understanding.”
Originally published on Live Science.